Remove personal data before you ask ChatGPT
Paste a text or drop a PDF. Names, IBANs, phone numbers and ID numbers become tags like [NAME 1], so the AI gets the facts without your identity. Then paste its answer back here to see your real details again. Nothing leaves this tab.
1Your document
2Check what gets replaced, then copy
Automatic detection can miss things, especially names without a label. Read the text before you send it. Tip: ask the AI to keep tags like [NAME 1] unchanged in its answer.
3Put your details back in the answer
Runs in your browser. Turn Wi-Fi off and try it.
What a chatbot receives when you upload a document
When you paste a payslip or upload a bank statement to ChatGPT, Claude or Gemini, the whole document goes to the company that runs the chatbot: your name, your address, your account number, sometimes your social security number. It is stored on their servers with your conversation. You can often turn off the use of your chats for training, but the copy has still left your hands. In 2025, a court order in a copyright case required OpenAI to keep ChatGPT conversations for months, including ones users had deleted.
France's data protection authority is direct about it. In its questions and answers on generative AI, the CNIL advises users of public chatbots to "never share confidential information such as personal data" (our translation).
The AI needs your numbers, not your name
To explain a payslip line, check a bank fee or summarise a contract, the AI needs the amounts, the dates and the wording. It doesn't need to know who you are. This tool keeps everything that matters for the question and swaps the rest for tags:
- Payslip: gross and net pay, contributions and dates stay. Your name, social security number, address and IBAN become [NAME 1], [ID 1], [ADDRESS 1] and [IBAN 1].
- Bank statement: amounts and merchants stay. Your account number, card number and address go.
- Contract or letter: the clauses stay. The names, emails and phone numbers of everyone involved become tags, each person with their own number, so the AI can still tell them apart.
The same value always gets the same tag, even if it's written twice in different ways, so the answer stays consistent. When the AI replies, paste its answer in step 3 and the real details come back, on your device only.
Sending a document to a person instead?
Tags are for asking an AI. To send a document to a landlord, an employer or a court, you want a copy with the personal data blacked out for good, and nothing left underneath. Use the Sumi app: it finds personal data in PDFs and scans, you choose what goes, and it burns the black boxes into a clean copy.
Questions
Is my text sent anywhere?
No. Detection, the tags and the restore step all run in this browser tab. Once the page has loaded, you can turn Wi-Fi off and it still works. The list of tags is kept in memory only and disappears when you close the tab or click Clear.
Is it safe to upload my payslip or bank statement to ChatGPT as it is?
It carries your name, address, account number and often a social security number, and once you upload it, you no longer control where those copies go. France's data protection authority, the CNIL, advises users of public chatbots never to share confidential information such as personal data. Replace them with tags first: the AI only needs the numbers.
Will the AI still understand my document?
Yes. Amounts, dates, job titles and the structure of the text stay as they are. The AI sees [NAME 1] instead of a name, and can still explain a payslip line, summarise a contract or draft a reply. Ask it to keep the tags as they are in its answer.
How do I get my real details back in the answer?
Paste the AI's answer in step 3. Every tag such as [NAME 1] or [IBAN 1] is replaced with the original value, here in your browser, and you can copy the personal version.
Is the result anonymous?
Not in the legal sense. As long as you keep the list of tags, the text can be linked back to people, which data protection law calls pseudonymisation. It still keeps names and numbers away from the chatbot. If you need data that can never be linked back, remove the details instead of tagging them, and check that nothing else points to the person.
What can it miss?
Names that appear without a label or title, nicknames, and details written in an unusual format. Read the text before you send it, and add anything left over with Also replace. Scanned pages have no text to read here: redact those in the Sumi app.